摘要：Following previous work on the changes in chemical and physical constants after oxidation of methyl linoleate by oxygen at 110°, the same oxidation was carried out at 70 and 90° to improve reproducility of some of the constants. As a result, rate of change in some of the constants decreased and reproducibility was improved. The infrared spectra of the product after oxidation of methyl linoleate under these conditions showed that its double bonds had shifted from the non-conjugated cis-cis form to conjugated trans-trans form, with an increase in peroxide value. The peroxide formed by the oxidation of methyl linoleate was examined by thin-layer chromatography and polarography. The antioxidative effect of butylhydroxyanisole and synergetic effect of citric acid were clearly observed. Even when iron was removed from the sample tested as completely as possible, the synergetic effect of citric acid did not vary and this fact indicated that this effect was not due to the masking of heavy metals by this acid. Synergetic effect of erythorbic acid was further examined.
